The Intervention Core's overall goal is to advance the science on nursing interventions to prevent or manage chronic illness in vulnerable populations. With the prevalence of chronic illness, it becomes increasingly important to develop and test nursing interventions to prevent and manage chronic illness. There is a substantial body of descriptive literature 'Dn what it is like to live with a chronic illness, however, a great deal of the work languishes at that stage and never moves to the development of interventions. The Specific Aims of the Intervention Core are to 1) facilitate movement of investigators from descriptive research to the development and testing of interventions, 2) explore the mechanisms of action of interventions by examining the mediators of selected outcomes, 3) help investigators evaluate the differential effectiveness of tested interventions by exploring moderators of treatment effect, with particular emphasis on the role of indicators of vulnerabilities as potential moderators, 4) explore the use of tailored interventions by identifying the contexts and problems for which they are most applicable, and 5) advance knowledge of cost analysis techniques and increase the use of cost benefit and cost effectiveness analyses in intervention studies. The Intervention Core will employ the following strategies to achieve its aims: consultation on problem identification and intervention design; consultation on statistical techniques for the analysis of mediators and moderators of intervention effects; consultation on cost analysis; seminars and colloquia; and continuing education programs on designing interventions for researchers in other institutions throughout the region.